Module com.darkcollective.relix.plan
Package com.darkcollective.relix.plan

Record Class PhysicalNode.Project

java.lang.Object
java.lang.Record
com.darkcollective.relix.plan.PhysicalNode.Project
All Implemented Interfaces:
PhysicalNode
Enclosing interface:
PhysicalNode
public static record PhysicalNode.Project(Schema schema, List<ProjectedAttribute> attributes, PhysicalNode input) extends Record implements PhysicalNode
Projection (π) — computes attributes from each row, streaming.

It keeps its input's row order, so it delivers the longest prefix of the input's ordering whose every key it projects, named as the output names it: over τ price * qty DESC, π item, price * qty → total delivers total DESC.

  • Constructor Details

    • Project

      public Project(Schema schema, List<ProjectedAttribute> attributes, PhysicalNode input)
      Creates an instance of a Project record class.
      Parameters:
      schema - the value for the schema record component
      attributes - the value for the attributes record component
      input - the value for the input record component

  • Method Details

    • children

      public List<PhysicalNode> children()
      Description copied from interface: PhysicalNode
      Direct child plans, left-to-right; empty for a PhysicalNode.Scan.
      Specified by:
      children in interface PhysicalNode

    • deliveredOrdering

      public Ordering deliveredOrdering()
      Description copied from interface: PhysicalNode
      The Ordering that this node delivers on its output stream. The default implementation returns Ordering.none() — meaning no guaranteed row order — which is the conservative safe answer for any operator that does not propagate or establish an ordering. Individual nodes that do preserve order (PhysicalNode.Select, PhysicalNode.Limit), carry it under new column names (PhysicalNode.Project, PhysicalNode.Rename) or establish it (PhysicalNode.Sort) override this method.
      Specified by:
      deliveredOrdering in interface PhysicalNode
      Returns:
      the delivered ordering; never null

    • toString

      public final String toString()
      Returns a string representation of this record class. The representation contains the name of the class, followed by the name and value of each of the record components.
      Specified by:
      toString in class Record
      Returns:
      a string representation of this object

    • hashCode

      public final int hashCode()
      Returns a hash code value for this object. The value is derived from the hash code of each of the record components.
      Specified by:
      hashCode in class Record
      Returns:
      a hash code value for this object

    • equals

      public final boolean equals(Object o)
      Indicates whether some other object is "equal to" this one. The objects are equal if the other object is of the same class and if all the record components are equal. All components in this record class are compared with Objects::equals(Object,Object).
      Specified by:
      equals in class Record
      Parameters:
      o - the object with which to compare
      Returns:
      true if this object is the same as the o argument; false otherwise.

    • schema

      public Schema schema()
      Returns the value of the schema record component.
      Specified by:
      schema in interface PhysicalNode
      Returns:
      the value of the schema record component

    • attributes

      public List<ProjectedAttribute> attributes()
      Returns the value of the attributes record component.
      Returns:
      the value of the attributes record component

    • input

      public PhysicalNode input()
      Returns the value of the input record component.
      Returns:
      the value of the input record component